Two-piece? (4)
I believe the answer is:
duet
This clue is a double definition.
'two' is the first definition.
(duet is a kind of two)
'piece?' is the second definition.
(I know that duet is a type of piece)
(Other definitions for duet that I've seen before include "Musical piece for two performers" , "Work for two players" , "Performance by company, perhaps" , "Composition for two performers" , "Work for a couple" .)